Allogeneic hematopoietic stem cell transplantation following donor CIK cell infusion: A phase I study in patients with relapsed/refractory hematologic malignancies

Patients with relapsed/refractory hematologic malignancies after allogeneic stem cell transplantation have a poor prognosis due to the high rate of relapse. Techniques capable of decreasing post-transplantation relapse rates are urgently sought. This study aimed to explore the feasibility and safety of allogeneic hematopoietic stem cell transplantation (HSCT) following infusion of donor cytokine-induced killer (CIK) cells. CIK cells were generated in vitro from donor peripheral blood mononuclear cells, and were phenotyped using flow cytometric analysis. CIK cells were administered to 15 high-risk relapsed/refractory hematologic malignancy patients who were not in complete remission in multiple infusions. These patients also received allogeneic HSCT. The side effects and outcomes were recorded. All patients achieved engraftment and complete remission. After CIK cell infusion, two patients developed graft-versus-host disease (GvHD), which was controlled by additional immunosuppressant drugs. At the last follow-up, nine patients had died and six patients were surviving at a median follow-up of 1513 days (range, 771-1655 days). In conclusion, allogeneic HSCT combined with sequential infusion of donor CIK cells is well tolerated in salvage relapsed/refractory hematologic malignancy patients.